Double security level in an incoherent optical communication system using combined modulation formats

Summary form only given. Presents a novel incoherent optical keying approach. By using combined modulation formats over the same optical carrier and in a very similar fashion, of both the information and key, both data streams bury each other. The modulated data can possibly be extracted only with a-priori knowledge of the key parameters. In the computer experiments presented here, double security level is achieved by using frequency-to-frequency together with time-to-frequency coding algorithms.